Copyright (C) 1999, 2000 David E. Nelson Updated 2003 by Henning Meier-Geinitz OVERVIEW This README addresses issues regarding how to configure the kernel to access a USB scanner. Although the driver was originally conceived for USB HP scanners, it's general enough so that it can be used with most other USB scanners. Also, one can pass the USB Vendor and Product IDs using module parameters for unknown scanners. There are two drivers for SCSI-over-USB scanners: * The "hpusbscsi" module for Hewlett-Packard 53xx series, Hewlett-Packard 7400, Minolta Scan Dual II, Minolta Elite II * The "microtek" module for the Microtek Scanmaker X6 In addition to the kernel driver, user-space tools like SANE are necessary to actually use the scanner. SANE ("Scanner Access Now Easy") provides drivers for a variety of USB scanners. See the appropriate SANE man page for details, e.g. man sane-usb and man sane-hp (for HP scanners). NOTE: Just because a product is detected by this driver does not mean that applications exist that support the product. It's in the hopes that this will allow developers a means to produce applications that will support the listed USB products. ADDITIONAL INFORMATION http://www.linux-usb.org/ (General information, mailing lists, links) http://www.mostang.com/sane/ (SANE user-space tools) http://www.meier-geinitz.de/kernel/ (USB scanner driver information and patches) REQUIREMENTS A host with a USB port. Ideally, either a UHCI (Intel), OHCI (Compaq and others) or EHCI hardware should work. Using "make menuconfig" or your preferred method for configuring the kernel, select "Support for USB", "OHCI/UHCI/EHCI" depending on your hardware, "USB Scanner support", and "Preliminary USB device filesystem". Compile and install the modules (you may need to execute "depmod -a" to update the module dependencies). If any of the USB sections were compiled into the kernel, a reboot is necessary. NOTE: Updating the boot disk with "lilo" may also be required. Testing was performed only as modules, YMMV. Up to 16 scanners can be connected/used simultaneously. If devfs support is enabled, see next section. Otherwise, the device files must be created manually if they don't exist yet, either by MAKEDEV or mknod. MAKEDEV method: cd /dev MAKEDEV usb Check that the device files "/dev/usb/scanner0" - "/dev/usb/scanner15" have been created. mknod method: mknod /dev/usb/scanner0 c 180 48 mknod /dev/usb/scanner1 c 180 49 . . mknod /dev/usb/scanner15 c 180 63 Set appropriate permissions for /dev/usb/scanner[0-15] (don't forget about group and world permissions). Both read and write permissions are required for proper operation. For example: chmod 666 /dev/usb/scanner0 Load the appropriate modules (if compiled as modules): modprobe usb-ohci (or uhci, usb-uhci, ehci) modprobe scanner DEVFS The later versions of the Linux kernel (2.4.8'ish) included a dynamic device filesystem call "devfs". With devfs, there is no need to create the device files as explained above; instead, they are dynamically created for you. For USB Scanner, the device is created in /dev/usb/scannerX where X can range from 0 to 15 depending on the number of scanners connected to the system. To see if you have devfs, issue the command "cat /proc/filesytems". If devfs is listed you should be ready to go. You should also have a process running called "devfsd". In order to make sure, issue the command "ps aux | grep '[d]evfsd'". CONCLUSION That's it. SANE should now be able to access the device. To make sure the device was detected, use "cat /proc/bus/usb/devices". Your scanner should be listed and the line starting with "I:" should look similar to this example: I: If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=usbscanner The important part is "Driver=usbscanner". If it reads "Driver=(none)", the USB scanner driver didn't recognize the scanner. Have a look at the MODULE PARAMETERS section for what to do in this case. For more details on the format of "/proc/bus/usb/devices" see Documentation/usb/proc_usb_info.txt. MESSAGES usb_control/bulk_msg: timeout -- On occasions this message will appear in "/var/adm/messages", on the console, or both depending on how your system is configured. This is a side effect that scanners are sometimes very slow at warming up and/or initializing. In most cases, however, only several of these messages should appear and is generally considered to be normal. excessive NAK's received -- This message should be considered abnormal and generally indicates that the USB system is unable to communicate with the scanner for some particular reason. probe_scanner: Undetected endpoint -- The USB Scanner driver is fairly general when it comes to communicating to scanners. Unfortunately, some vendors have designed their scanners in one way or another that this driver doesn't account for. probe_scanner: Endpoint determination failed -- This means that the driver is unable to detect a supported configuration for means to communicate with the scanner. See also "probe_scanner: Undetected endpoint". funky result -- Most of the time the data flow between the computer and the scanner goes smoothly. However, due to whatever reason, whether it be solar flares or stray neutrons, sometimes the communications don't work as expected. The driver tries to handle most types of errors but not all. When this message is seen, something weird happened. Please contact the mailing list (see CONTACT section for details). MODULE PARAMETERS If you have a device that you wish to experiment with or try using this driver with, but the Vendor and Product IDs are not coded in, don't despair. If the driver was compiled as a module, you can pass options to the driver. Simply add options scanner vendor=0x#### product=0x**** to the /etc/modules.conf file replacing the #'s and the *'s with the correct IDs. The IDs can be retrieved from the messages file or using "cat /proc/bus/usb/devices". If the default timeout is too low, i.e. there are frequent "timeout" messages, you may want to increase the timeout manually by using the parameter "read_timeout". The time is given in seconds. This is an example for modules.conf with a timeout of 60 seconds: options scanner read_timeout=60 If the "scanner" module is already loaded into memory, it must be reloaded for the module parameters to take effect. In essence, "rmmod scanner; modprobe scanner" must be performed. BUGS Just look at the list of fixes in the source files. CONTACT For asking about problems and fixes, use the linux-usb-users mailing list. For patches, linux-usb-devel should be used. Information on both lists can be found on http://www.linux-usb.org/. CHANGES - Added information about read_timeout - Added more details about /proc/bus/usb/devices - Added/updated links - Added pointers two "special" scanner drivers - Reordering, spell-checking, formatting - Used /dev/usb/scanner[0-15] instead of /dev/usbscanner[0-15] - Removed some basic USB configuration stuff - Added EHCI - Removed some more references to HP - Amended for linux-2.4.12 - Updated devfs support - Amended for linux-2.3.99-pre6-3 - Appended hp_scan.c to end of this README - Removed most references to HP - Updated uhci/ohci host controller info - Updated support for multiple scanner support - Updated supported scanners list - Updated usbdevfs info - Spellcheck HP TEST PROGRAM There is a small test program (hp_scan.c -- appended below) that can be used to test the scanner device if it's an HP scanner that supports SCL (Scanner Control Language). Known HP scanner that support SCL are the 4100, 5200, 6200, the 6300 -- note that the 4200 is *not* supported since it does not understand SCL; it's also strongly suspected that the 3300 and the PhotoSmart S20 are not SCL compliant. Hp_scan.c's purpose is to test the driver without having to retrieve/configure SANE. Hp_scan.c will scan the entire bed and put the output into a file called "out.dat" in the current directory. The data in the file is raw data so it's not very useful for imaging. --------------- snip -- hp_scan.c -- snip --------------- /* This is a really crude attempt at writing a short test program. It's mostly only to be used to test connectivity with USB HP scanners that understand SCL. Currently, the supported models are 4100C, 5200C, 6200C, and the 6300C. Note that the 4200C is *NOT* acceptable. Copyright (C) David E. Nelson , 1999 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. */ #include #include #include #include #include /* Gray Output produces about a 8945400 byte file. Color Output produces a 26836200 byte file. To compile: gcc -o hp_scan hp_scan.c */ // #define COLOR /* Undef to scan GrayScale */ int send_cmd(int, const char *, int); int read_cmd(int, char *, int); int main(void) { ssize_t cnt = 0, total_cnt = 0; FILE *fpout; int fp; int data_size = 32768; char *data; static char reset_cmd[] = {'\x1b','E'}; #ifdef COLOR static char data_type_cmd[] = {'\x1b','*','a','5','T'}; /* Color */ static char data_width_cmd[] = {'\x1b','*','a','2','4','G'}; /* 24 Bit Color */ #else static char data_type_cmd[] = {'\x1b','*','a','4','T'}; /* Gray */ static char data_width_cmd[] = {'\x1b','*','a','8','G'}; /* 8 Bit Gray */ #endif static char query_cmd[] = {'\x1b', '*', 's', '2', '5', '7', 'E'}; static char start_scan_cmd[] = {'\x1b','*','f','0','S'}; if(!(data=malloc(data_size))) { perror("malloc failed"); exit (1); } if((fp=open("/dev/usb/scanner0", O_RDWR)) < 0) { perror("Unable to open scanner device"); exit (1); } if((fpout=fopen("out.dat", "w+")) == NULL) { perror("Unable to open ouput file"); exit(1); } send_cmd(fp, reset_cmd, sizeof(reset_cmd)); send_cmd(fp, data_type_cmd, sizeof(data_type_cmd)); send_cmd(fp, data_width_cmd, sizeof(data_width_cmd)); send_cmd(fp, start_scan_cmd, sizeof(start_scan_cmd)); while ((cnt = read(fp, data, data_size)) > 0) { printf("Read: %u\n", cnt); if(fwrite(data, sizeof(char), cnt, fpout) < 0) { perror("Write to output file failed"); exit (1); } total_cnt += cnt; } if (cnt < 0) { perror("Read from scanner failed"); exit (1); } printf("\nRead %lu bytes.\n", total_cnt); send_cmd(fp, reset_cmd, sizeof(reset_cmd)); close(fp); fclose(fpout); return (0); } int send_cmd(int fp, const char * cmd, int length) { int result; int x; if((result = write(fp, cmd, length)) != length) { printf ("Write warning: %d bytes requested, %d written\n"); } else if (result < 0) { perror ("send_cmd failure"); exit (1); } return (result); } int read_cmd(int fp, char * response, int length) { return read(fp, response, length); }